Technological Field
The present invention relates to an image forming apparatus that transfers and fixes a toner image that is formed on an image carrier to a sheet of paper, and forms an image.
Description of the Related Art
Image forming apparatuses that form images on sheets of paper using toner have been known. In such image forming apparatuses, the surface of a photoconductor drum, which is an image carrier, is charged according to an image and a latent image is formed. In a process called developing, a developing device then deposits toner on the latent image on the photoconductor drum and reveals the latent image to form a toner image
The toner image formed on the photoconductor drum is primarily transferred to an intermediate transfer member and is secondarily transferred, at a transfer unit, from the intermediate transfer member to a sheet of paper. The sheet of paper to which the toner image has been transferred is conveyed to a fixing unit, and the toner image is fixed on the sheet of paper by applying heat and pressure.
Configurations are proposed for such image forming apparatuses in which a developing device has two developer rollers that face the photoconductor drum. In image forming apparatuses, it is necessary to ensure a predetermined alignment between the photoconductor drum and the developing device. Thus, a configuration in which one of the two developer rollers can be aligned relative to the photoconductor drum is proposed (see, for example, JP 2003-307930 A).
In addition, a configuration which includes a pressing member that presses the developing device toward the photoconductor drum and a pressing member that presses one of the two developer rollers toward the photoconductor drum is proposed (see, for example, JP 2002-351211 A). Furthermore, a configuration which includes a pressing member that presses the developing device toward the photoconductor drum by restricting the direction of movement of the developing device to a substantially horizontal direction moving toward and away from the photoconductor drum is proposed (see, for example, JP 2013-156364 A).
In the image forming apparatus disclosed in JP 2003-307930 A, when a force is generated in a direction in which the developing device rotates, the developing device rotates and the developer roller that has no abutment becomes misaligned. In the image forming apparatus disclosed in JP 2002-351211 A, the developing device requires a configuration for pressing the developer roller, which complicates the structure. Furthermore, in the image forming apparatus disclosed in JP 2013-156364 A, a reduction in the force for pressing the developing device toward the photoconductor drum makes the alignment of the developer roller relative to the photoconductor drum difficult.
In a conventional image forming apparatus, increasing the force for pressing the developing device toward the photoconductor drum ensures the predetermined alignment between the photoconductor drum and the developer roller. However, increasing the force for pressing the developer roller against the photoconductor drum can deform the photoconductor drum and the developer roller.